A non-volatile memory is a computer readable storage medium capable of maintaining stored data even when disconnected from a power source for an extended period of time. Floating gate memory is a type of non-volatile memory which uses high voltages, e.g., greater than 10V, to program and erase data stored in a memory cell. Charge trapping memory is a type of non-volatile memory which uses lower voltages, e.g., less than 8V, to program and erase data stored in a memory cell. Floating gate memory is capable of storing data for a longer period of time than charge trapping memory, due to the higher potential barrier for the floating gate memory.
A process for forming floating gate memory is different from a process for forming charge trapping memory. In some instances, a size of transistor structures in each type of non-volatile memory is different. Different charge storing materials are used in the floating gate memory than in the charge trapping memory. Doping concentrations and depth of wells and lightly doped drain (LDD) regions are different in the floating gate memory than in the charge trapping memory.
Due to these differences, the processes for forming floating gate memory and charge trapping memory are separately optimized. As a result, separate masks and layout designs are used during the process for forming each type of non-volatile memory.